Semi-Dirac Semimetal in Silicene Oxide

TL;DR

This paper proposes a theoretical method to realize semi-Dirac semimetals in honeycomb materials, specifically predicting silicene oxide as a candidate through covalent modification and strain engineering.

Contribution

It introduces a novel approach combining covalent addition of group-VI elements and strain engineering to induce semi-Dirac semimetal properties in silicene oxide.

Findings

Silicene oxide (Si2O) is predicted to be a semi-Dirac semimetal.

The approach involves covalent modification and strain engineering.

Analysis of p-orbital frustration explains the band structure changes.

Abstract

Semi-Dirac semimetal is a material exhibiting linear band dispersion in one direction and quadratic band dispersion in the orthogonal direction and, therefore, hosts massless and massive fermions at the same point in the momentum space. While a number of interesting physical properties have been predicted in semi-Dirac semimetals, it has been rare to realize such materials in condensed matters. Based on the fact that some honeycomb materials are easily oxidized or chemically absorb other atoms, here, we theoretically propose an approach of modifying their band structures by covalent addition of group-VI elements and strain engineering. We predict a silicene oxide with chemical formula of Si2O to be a candidate of semi-Dirac semimetal. Our approach is backed by the analysis and understanding of the effect of p-orbital frustration on the band structure of the graphene-like materials.